1. Field
Example embodiments relate to a phase-change random access memory (PRAM) and programming method for a phase-change random access memory (PRAM), and for example, to a phase-change random access memory (PRAM) and programming method for programming an amorphous state to control a threshold voltage of a PRAM.
2. Description of Related Art
Conventional phase-change random access memories (PRAMs) may use a resistance difference between amorphous and crystalline phases of chalcogenide. Conventional PRAMs may have disadvantages that a higher current may be required for a phase change and/or sizes of cells included in a PRAM may be larger.
Conventional PRAMs may be programmed using a threshold voltage difference without a phase change. Conventional PRAMs may be characterized in that an access transistor may not be required for each cell included in a PRAM due to self-rectification and/or a higher density design may be possible.
However, conventional PRAMs may implement programming through control of a pulse magnitude corresponding to a heating power of a chalcogenide material. For example, a magnitude of a programming pulse for programming a programming area (for example, an amorphous area) of the chalcogenide may be varied in magnitude or duration. Accordingly, achieving reliable programming may be problematic.